In some cases, a communication system which includes base station apparatuses and mobile station apparatuses is operated in a state in which transmission power from part of the base station apparatuses is reduced or transmission output therefrom is stopped. For example, an amount of traffic processed by base station apparatuses or power consumption of base station apparatuses is measured, and on/off of transmission power or a transmission output of a base station apparatus is controlled according to the traffic amount.
Such processing includes, for example, energy saving studied in 3GPP (The 3rd Generation Partnership Project). The “energy saving” is also referred to as “ES” in the following illustration.
In addition, a communication area estimating server is known which includes: a receiving unit which receives one or a plurality of pieces of signal information, which is stored in a mobile telephone positioned outside a range of a mobile communication network and relates to signals from radio signal sources, from a mobile telephone when the mobile telephone moves into the range of the mobile communication network; a calculating unit which calculates the position of the mobile telephone when the mobile telephone receives a signal related to signal information, based on one or a plurality of pieces of received signal information; and an estimating unit which estimates a position outside the range of the mobile communication network, based on the calculated position of the mobile telephone.
Further, a mobile communication system is proposed which reduces power consumption by changing a zone configuration of radio base stations depending on a communication traffic state of the system and prevents a communication unavailable area from being generated by changing the zone configuration. This system includes: a group of radio base stations which is formed by arranging one master radio base station which has a variable radio output level and a plurality of slave radio base stations which can stop radio output levels and can be set only to radio receiving operations; and a radio control station which controls the radio base stations of the group, and performs call connection control with switching equipment. The radio control station includes: a unit which collectively monitors communication traffic notified from the radio base stations of the group; a unit which collectively monitors electric field intensities from the master radio base station notified from respective slave radio base stations in the group; a unit which transmits radio output variable control signals to radio base stations of the group; and a database which manages an arrangement configuration of the master radio base station and the plurality of slave radio base stations.
Related art is disclosed in Japanese Laid-open Patent Publications No. 2010-130523 and No. 10-145842.